We construct new estimates on the Galactic escape speed at various Galactocentric radii using the latest data release of the Radial Velocity Experiment ( RAVE DR4 ) .
Compared to previous studies we have a database larger by a factor of 10 as well as reliable distance estimates for almost all stars .
Our analysis is based on the statistical analysis of a rigorously selected sample of 90 high-velocity halo stars from RAVE and a previously published data set .
We calibrate and extensively test our method using a suite of cosmological simulations of the formation of Milky Way-sized galaxies .
Our best estimate of the local Galactic escape speed , which we define as the minimum speed required to reach three virial radii R _ { 340 } , is 533 ^ { +54 } _ { -41 } km s ^ { -1 } ( 90 % confidence ) with an additional 4 % systematic uncertainty , where R _ { 340 } is the Galactocentric radius encompassing a mean overdensity of 340 times the critical density for closure in the Universe .
From the escape speed we further derive estimates of the mass of the Galaxy using a simple mass model with two options for the mass profile of the dark matter halo : an unaltered and an adiabatically contracted Navarro , Frenk & White ( NFW ) sphere .
If we fix the local circular velocity the latter profile yields a significantly higher mass than the uncontracted halo , but if we instead use the statistics on halo concentration parameters in large cosmological simulations as a constraint , we find very similar masses for both models .
Our best estimate for M _ { 340 } , the mass interior to R _ { 340 } ( dark matter and baryons ) , is 1.3 ^ { +0.4 } _ { -0.3 } \times 10 ^ { 12 } ~ { } M _ { \sun } ( corresponding to M _ { 200 } = 1.6 ^ { +0.5 } _ { -0.4 } \times 10 ^ { 12 } M _ { \sun } ) .
This estimate is in good agreement with recently published independent mass estimates based on the kinematics of more distant halo stars and the satellite galaxy Leo I .